Folded paperboard cartons have long been used as inexpensive biodegradable containers for fast food for example, hamburgers, pizza, and the like.
Such containers frequently comprise a tray and a lid integrally formed therewith from a unitary blank, both the tray and lid having peripheral corner-joined walls with the lid walls overlying the tray walls in the closed carton. The provision of fixed upstanding walls on the conventional tray of such cartons has conventionally been considered necessary to ensure sufficient strength and stability. However, such tray walls tend, depending upon the foodstuff, to restrict access to the tray, both when introducing the foodstuff and particularly in those instances where the consumer wishes to use the tray in the manner of a plate or dish from which the foodstuff is directly consumed. For example, pizza is most easily consumed from a flat dish or platter as opposed to a walled bowl-type container. Also, the conventional wall-enclosed tray forms corners in which foodstuff can be trapped.
Nevertheless, as the conventional folded paperboard carton has inherent advantages of being economically feasible for a disposable item, biodegradable, and the like, the lack of particular or desirable features is frequently considered a necessary compromise.
As a further example, known fast food cartons frequently utilize elaborate latching or locking mechanisms to ensure a positive securing of the closed cover. Such mechanisms can be both difficult to engage and difficult to disengage, and frequently lead to destruction of the mechanism when opened by a consumer, thereby precluding a proper reclosing of the carton.